Dashpot



F. LJUNGSTROM.

DASHPOT.

APPLICATION FILED OCT. 14, 1920.

11,36,879 Patented Aug. 9, 1921.

o iil 1 .I' II 0 3 i. 6)

5 m I m ''00. A I

I \9 -09 aw 2%; v m N [I 00 Q Inventor:

FT-edrikLjunfi/lrjln, b a: g Q 8 l-l isAtLor ngg.

nnrr

rnnnnix Launes'rsoivr, or BREVIK, Lnonieon, SWEDEN, assrsuon 'ro AK'IIE-BOLAGET LJ'UNGSTROMS anerusnrn, or sxlinsli'rna, swnnnn.

' nasnror.

To all whom z'tmay concern:

Be it known that I, Fnnnnrx LJ NG- s'rRoM, a subjectof the King ofSweden, residing at Brevik, Lidingon, Sweden, have invented certain newand useful Improvements in Dashpots, of whichthe following is aspecification. V The present invention relates to dashpots intended foruse in reducing or dampening axial vibrations of'a rotor member whichhas a limitedamount of axial play. One application of my invention is inconnection with elastic fluid turbines for reducing I axial vibrationsof a rotor or rotors thereof,

and it is particularly intended for use with radial flow turbines havingoppositely ro-- tating wheels in which the axial thrust is balanced bymeans of pressure disks upon which elastic fluid acts, the pressureincreasing and decreasing on such disks when the wheels move axially,thereby maintaining such wheels in correct position.

My invention relates particularly to dash,- pots of the type comprisinga cylinder filled with a liquid such as oil, anda piston, the cylinderand piston being axially movable relatively to each other, and thecylinder spaces on opposite sides of the piston being connected by apassage of restricted area, the arrangement being such that while itpermits of slow relative axial movement, it dampens out and preventsquick vibratory movements. j

In such dash pots, particularly where oil is used as the liquid, it isimportant that all air be separated from the liquid since the presenceof air in the liquid renders the liquid more or less elastic which isobviously detrimental to the efiicient operation of the dash-pot.

The object of my invention is to provide an improved dashpot of theabove'referred to character which among other features embodies anarrangement whereby air is cfficiently separated from the liquid as theliquid entersthe dash-pot, and for a considerationof what I believe tobe novel and my invention, attention is directed to the accompanyingdescription and the claims appended thereto.

In, the drawing Figure l is an axial, sectional viewofa dash-potembodying my invention; and Fig. 2 is an end view thereof.

Referring to the drawing, 5 indicates a Specification of Letters Patent.Pgmygntgd A i g, 9, 15521,

Application filed October 14, 1920. Serial No. 416,944.

cylinder of a dash-pot. In casing 8 is a pis ton 10 which may moveaxially therein, but 1s held from rotation by means of a bolt 11 whchpasses through casing 8 and enters a recess in the periphery of piston10, which recess is of such length as to permit of the desired amount ofaxial movement of shaft 5. Shaft 5 passes freely through an opening inthe center of piston 10, therebeing a bearing lining 12 in such openingon which the shaft runs.

Carried by shaft'5 in casing 8 and located on opposite sides of piston10 are two pressure disk 13 and'14, the disk 13 being formed integralwith shaft 5 and the disk 14 being suitably keyed or otherwise fastenedto shaft 5 so as to turn therewith. Disk 14 may be adjusted axiallyalong shaft 5 and is held from axial movement by nuts 15 which arelocked against turning by a locking washer 15 Between each pressureShaft 5 is journaled in bearings disk and the adjacent surface of piston10 are arranged a number of ring segments 16 which are held by studs 7.?projecting from disks 13 and 1%. In the present instance three ringsegments are shown on each disk and each is held by a single stud 17,the segmentsbeing prevented from turning on the studs by flanges 18 atthe peripheries of the pressure disks. Ring segnients lti are spacedapart circumferentially so as to leave radially extending passages 19between them,- which communicate at their inner ends with annularchambers 20. The surfaces of ring segments 16 which bear against piston10 are provided with bearing linings 21 and the segments may be broughtinto firm engagement with the piston by screwing up nuts 15. Shaft 5 isprovided with an axially extending 0pening 22 which is connected byholes 23 with chambers 20. .The cylinder chambers on opposite sides ofpiston 10 are thus connected to each other by way of holes 23 andopening 22. The outer end of shaft through a supply pipe 26 which feedsliquid I throughchannels 27 in piston 10 to chambeers 20. Reverse flowof liquid through 7 pressure disks 13 and 1a and ring segments I6.Piston 10, however, remains stationaryfrmg segmentsv 16'rotat1ng on 1t.

axial movement of piston lOinthe same di rect1on and since the cylmder 8is entirely filled with liquid, this. can only takeiplace by thetransfer of such liquid "fromone side of. piston lOto the otherthroughholes 23 and opening 22, Holes 23 are of limited parea so that any,quick movements roli'the piston are prevented. bythe liqui'd, ,becauseit will not have timeto passothrou'gh' holes 23. Any vibrations are thuswholly or par tially prevented or damped out. However,

a gradual, limited axial movement of the piston inthe cyinder ispermitted? within thelimits of bolts 11. v r

v Liquid is being continuously forced into cylinder 8 through supplypipe26to make up the deficiency caused by leakage of:liq-' uid from thecylinder, and it, is'important that all air be separated from thisliquidsince the presence of any; air in-the' liquid has an injurious influenceon its consistency renderingit more or-les elastic. improved structureand arrangement of dash-pot, I' effectively separate air from 'theliquid in the following manner,-=-

, The liquid entering through channels 27 isfed into annular chambers 20from whence itj'is forced radially outward 7 through the passages 19between ring segment 16,,the

action being in the nature of a pumping operation. This pumping actionmust take place against the pressure of the liquid 7 filling cylinder 8and as'a resultthe heavier liquid is thrown radiallyoutward while anyair together with excess-of liquid will be I forced'through or flowthrough holes 28jinto opening 22 froml whenceit will escape throughholes 31 and thebearing 7' to'cham'e. ber 30 from which it isfdischargedby pipe 32. I

' 'Inlaceordance withthe provisions of the patent statutesQI havedescribed the prin'civ pile of operation of invention, togetherWlth;.l':l16 apparatus which I-"nowfc'onsider to .represent the "bestembodiment thereof,

2 but I 'desireito haveit understood that the apparatus shown is onlyillustrative and that the invention maybe carried out by other means. .7

A w "axial displacement of shaft 5 requires an,

/Vhat I claim a s/new and desire to-secure by Letters Patent oftheUnited'States, 1s I '1. In an apparatus of the characterdescribedfthe combination: of a 'cylinder, at v v shaft, journaled inwalls of the cylinder, an

axially movableflnon rotatable piston in the 'c'ylindeninemb'ers carriedbythe shaft and I engaging the pistonon opposite sides,me anstor'supplying liquid to the cylinderfand means carried by said membersforseparatin air from such liquid. 7 V r j Y 2. In an apparatus of 'thecharacter described, the combination: Offit cylinder, a shaft journaled;in 'wall of the. cylinder, an axially movable nonrrotatable-piston inthe cylinder, said shaft; passing througha-n opening in-the center ofthe piston,;pressure members carried by the shaft and engaging thepiston on opposite' sides, Ineanstorgsup plying liquidto the cylinder atpoint-adjacent said shaft,- said means including' a radial passage- 1n 7sald piston, and Smeans carried by said pressure members' foriseparatingalr from suchllquld;

3. Inan, apparatus of the. character-tie 190 scribed, the combinationof. a cylindenan axially movable nonrotatable-piston therein, 1a shaftjournaled'in Walls-of-the cylinder, saidshaft passing through an opening7 in thecenter of thepistom'pressure members carried by thefshaft' andengaging the piston on opposite si.de s,meansl for supplying liq- H uidto the cylinder ata-lpoint-adjacent said 7 shaft, sald meansincludmg a'radial passage 1 nsald p1ston,,-and;means carried by sa d said liquid,SEI-ldfillttft being'provided with passages for conveying air outsidethe cyl inderv 4. In an apparatus of the character de- 10a scribedythecombination of a" cylinder-fa shaft journaled in walls-of thecylinder-,an" axially movable non-rotatable piston iin th'e opening inthe center ofthe'piston', aindibecylinder, said shaft passingthrough; an

ing provided] with passages of restricted area which connect thecylinder 'spaces on opposite sides" of the piston, pressure diskscarried'b'y the shaft on opposite sides of the piston,- ring segments onsaid pressure disks which engage said piston, and, means for a;

V supplying 'liquid't'o the cylinder at. points;

adjacent the central portion. of said pressure disks, said firingsegments servingto separate alr from the l quidsupplijedflby centr fugalactlon on 'suchl1qu1d. 1

nan apparatus of the; character scribed,.the combination ofa' cylinder,a

shaft '1' ournaledfin .walls of v the; cylinder, an; axially imovable'non-rotatable piston in the;

opening-in the; center of'ithe piston',aan d be mg prov ded w1th a lpassage of-grestricted ji area which conne.cts;the cylinde'rzspace's onopposite; sides of the piston, pressure disks V 100 pressure membersforseparatlng a r from cylinder, said shaft passingithrbuglran 2.;

carried by the shaft on opposite sides of the centrifugal action on suchliquid, and said piston, ring segments on said pressure disks shaftbeing provided with passages for the which engage said piston and meansfor escape of such air. 10 supplying liquid to the cylinder at points InWitness whereof, I have hereunto set adjacent the central portions ofsaid presmy hand this 12th day of September, 1920. sure disks, said ringsegments serving to separate air from the liquid supplied by 'FREDRIKLJUNGSTRQM.

